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NITROGEN FIXATION . www.powerpointpresentationon.com. Introduction. Most Abundant Essential Organic Component Primary Nutrient Green Plants Fixed Nitrogen ?? Nitrogen Fixing organisms Diazatrophs Prokaryotes .
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NITROGEN FIXATION www.powerpointpresentationon.com
Introduction • Most Abundant • Essential Organic Component • Primary Nutrient Green Plants • Fixed Nitrogen ?? • Nitrogen Fixing organisms Diazatrophs Prokaryotes
Nitrogen Cycle : • What it is ?
Relationship b/w Organic & Inorganic N2 Metabolism. Atmospheric Nitrogen I
Breaking of N2 bonds Energy • Two Ways : Abiotic Fixation Biological Fixation
Abiotic Fixation • Result : Nitrates • Source: Lightening & Cosmic Radiations Nitrogen+ Oxygen Nitrogen Oxides (NO , NO2) Nitrogen Oxides + Water Nitric Acid
Biological Fixation Soil • Microrganisms Water
Cyanobacteria: • Imp. In Carbon and Nitrogen Cycle • Utilize variety of inorganic and organic sources of combined nitrogen such as nitrate, nitrite, ammonium
Nitrogen cycle • Series of natural processes by which nitrogen passes through successive stations in air, soil, and organisms. • The atmospheric nitrogen occur in an inert form (N2)/can’t be used by most of the orangnims. • Atmospheric nitrogen is fixed by nitrogen cycle. Which principally invovles:- • Nitrogen fixation. • Nitrification. • Assimilation. • Ammonification. • Dentrification.
Nitrogen fixation:- • Deposits into soil & surface water precipitation. • Once settled; undergo changes Conversion via Microorganisms: • Bacteria in symbiotic relation with plants. • Free aerobic bacteria/alga. • Cyanobactetria
Nitrification:- • Two step process; converts NH3/NH4+ to NO3. • In first step:- Nitrosomanas/nitrococcus (soil bacteria) convert NH3 to NO2-.
In second step:- Nitrobacter converts NO2- to NO3-. • Bacteria gain energy known as ( nitrifying bacteria).
Assimilation:- • Process by which plants/animals take up nitrates and ammonia. • Plants take up NO3- and NH4+ through their roots and integrate them into various plant proteins /nucleic acids. • Animals take up this nitrogen by consuming plant tissues.
Ammonification:- • Many bacteria and fungi convert nitrogen into ammoniumNH4+ known as ammonification. • Converted ammmonia become available to take part in other biological processes.
Denitrification:- • ‘Reduction of NO3+ N2 (anaerobic bacteria)’ • Pseudomonas/Clostridium (anaerobic conditions)
Ecological Implications of Human Alterrations to Nitrogen Cycle:- • Burning fossils fuels. • Primary productivity of many ecosystems. • Alterations in both aquatic/terrestrial ecosystems. • Argicultural systems (leach out of soil) • Haber-bosch process. • Anoxio/hypoxia. • Harmful algal blooms. • Change in boidiversty/overall ecosystem function. • Parasitic/infectious diseases (humans/wildlife). • Increased acidification in freshwater ecosystems.